The present invention relates to an artificial sphincter with magnetic control comprising a valve designed to be installed permanently on a biological duct or organ in the human body and provided with means of mechanically closing said duct comprising a first element which is sensitive to a magnetic field and means of magnetic control outside said human body and designed to activate said first element sensitive to a magnetic field.
There are known sphincter prostheses consisting of a toric balloon which tightly hugs the urethra, this balloon being able to be inflated by means of a small syringe made of flexible synthetic material and placed in a man""s testicles or a woman""s labia majora. An auxiliary reservoir, placed in the viscers and linked by tubes to the syringe and balloon, makes it possible to inflate or deflate the latter using a physiological fluid propulsed by the syringe. This reservoir houses a device making it possible to reverse the direction of flow of the fluid which inflates and deflates the balloon. The surgical installation of this urinary prosthesis is quite tricky as it is made up of three subassemblies linked to a pipe in which a physiological fluid flows. It can therefore present leakage risks, is relatively bulky and is insufficiently ergonomic which thereby contributes to the psychological discomfort of the patient. Furthermore, the size of the balloon can only be adjusted in notches and inflating it leads to folds which bring about excessive compression points on the urethra which may lead to a local necrosis of the tissues. Finally, the reservoir""s reversing device may jam, preventing the unit from operating.
This type of sphincter prostheses has been improved by providing a device for controlling the physiological fluid which is controlled by magnetic means outside the human body as divulged for example in the publications U.S. Pat. No. 053,952 and U.S. Pat. No. 5,562,598. Nevertheless, these sphincter prostheses remain complex because of the various components required and the risks of the physiological fluid leaking persist.
Other publications like for example FR-A-2 655 536 and FR-A-2 651 134 describe sphincter prostheses requiring the presence of a balloon to hold the prosthesis and collect the urine in the bladder. They are therefore tricky to put in place and require a flexible tube with its closing and opening mechanism to be permanently present in the man""s penis or the woman""s urinary meatus. This system of course causes the user considerable discomfort, particularly during sexual intercourse.
Other artificial sphincters do exist which do not operate with a physiological fluid but by means of a mechanical valve controlled directly by a magnetic field applied outside the human body, as described for example in publications FR-A-2 688 693 and U.S. Pat. No. 3,926,175. In the first publication, the artificial sphincter is comprised of a mechanical clip provided around the duct to be sealed and one of its branches is coupled to a solenoid controlled by an internal energy sensor. This sensor receives waves from a transmitter outside the human body, converts them and transmits them to the solenoid to open the clip. In the second publication, the artificial sphincter is made up of a mechanical valve, part of which comprises a permanent magnet activated by an electromagnet arranged outside the human body. In both cases, the magnetic control only controls the valve of the artificial sphincter in on-off mode, i.e. only opening or closing it. None of these devices makes it possible to adjust the degree to which this mechanical valve is closed.
In another application, there is also a sphincter prosthesis comprising an adjustable ring placed by means of surgery around the stomach for patients suffering from obesity, with the aim of helping them to lose weight. This device, comprised of a ring made of biocompatible flexible material, called a balloon, is fitted with a closing loop at its ends and is connected by a fill-up tube to an airtight housing which is closed by a flexible membrane. The surgeon positions this ring around the stomach and connects it to the filling housing placed under the skin. During a physical examination, the practitioner can then adjust the tightness of the ring by puncturing in the housing through the patient""s skin using a syringe and injecting or extracting a physiological fluid in the housing. This type of prostheses presents the drawback of being able to leak following injuries caused by the surgeon when putting it in place or following the formation of a hernia on the balloon""s flexible pocket. It also presents the drawback of not being able to be finely and simply adjusted as it causes pain when puncturing under the skin to adjust the balloon.
The aim of the present invention is to overcome these difficulties and drawbacks by proposing an artificial sphincter comprising a valve which is implanted during a surgical operation and can then be activated easily from outside the human body by the patient and is also easily adjustable from outside the human body during a postoperative examination by a doctor. This artificial sphincter is designed to have several applications given the fact that it can be adjusted either to totally seal or to constrain a duct, like for example the urinary urethra, the colon, the pylorus of the stomach, or any other duct, but also any other organ whether biological or not. This artificial sphincter thus makes it possible, for example, to overcome the problems of bladder or bowel incontinence, to change in a controlled and remote manner the opening of the pylorus in a human being or the contraction of an organ, be it biological or not.
This aim is achieved by an artificial sphincter as described in the preamble and characterized in that it comprises means of adjusting the degree of closure of said means of closing the duct comprising a second element sensitive to a magnetic field designed to be controlled by a magnetic field generated by second means of magnetic control outside said human body.
In a preferred form of embodiment, the valve comprises an airtight housing placed on said duct and provided with a support conduit arranged to receive said duct in the open position, the means of closing the duct and the means of adjusting the degree of closure being mounted inside said housing.
The means of closure advantageously comprise at least one strap arranged to compress said duct against a wall of said support conduit, one at least of its ends being fixed to the first element sensitive to a magnetic field, mobile in axial translation in said housing.
Preferably, the means of closure comprise a spring mechanism which is mobile in axial translation in said housing, arranged between said support conduit and said first element and arranged to exert pressure on this magnet so as to move it away from said support conduit to tighten the strap.
The means of closure can furthermore comprise a lower disk which is mobile in axial translation in said housing, arranged between the spring mechanism and the first element and fixed to the other end of the strap.
In the preferred form of embodiment, the means of adjusting the degree of closure of said means of closing the duct comprise an upper disk mounted by screwing it in said housing and comprising a second element sensitive to a magnetic field, this upper disk forming an axial stop for said means of closure.
A thrust ball bearing can be advantageously arranged between the means of closure and the means of adjustment so as to eliminate any friction to facilitate the rotation of said upper disk.
The first means of magnetic control can comprise an external magnet having its poles arranged axially, designed to be arranged substantially opposite said valve and arranged to move said first element axially in the direction of the support conduit to loosen the strap.
The second means of magnetic control can also comprise an external rotating magnet having its poles arranged in a plane perpendicular to its axis, designed to be arranged substantially opposite said valve and arranged to make said second element rotate.
This magnet can comprise a U-shaped metal structure coupled to a motor, this structure bearing a coil supplied with an electric current, the speed of the motor and/or intensity of the current being variable.
Likewise, this magnet can comprise metal lugs mounted at the ends of said structure, the spacing between these lugs being adjustable to adjust the radial position of the poles.
The first element and/or the second element sensitive to a magnetic field is advantageously made up of a magnet but can also be made up of a metal part in some alternatives.
In a quite advantageous manner, the airtight housing is filled with a physiological fluid which is used as a shock absorber for the moving organs and is made of rigid, biocompatible plastic materials, the ends of the support conduit being flexible to ensure tightness with said duct.